BRCAness as a prognostic indicator in patients with early breast cancer
Lei Liu, Yuki Matsunaga, Junji Tsurutani, Sadako Akashi‐Tanaka, Hiroko Masuda, Yoshimi Ide, Rikako Hashimoto, Mayuko Inuzuka, Chie Watanabe, Kanae Taruno, Terumasa Sawada, Hiromi Okuyama, Arisa Ata, Takashi Kuwayama, Sayuka Nakayama, Yumi Tonouchi, Seigo Nakamura
Abstract
BRCAness is defined as a phenotypic copy of germline BRCA mutations, which describes presence of homologous recombination defects in sporadic cancers. We detected BRCAness by multiplex ligation-dependent probe amplification (MLPA) and explored whether BRCAness can be used as a predictor of prognosis. BRCAness status was classified for total 121 breast cancer patients. Forty-eight patients (39.7%) were identified as BRCAness positive. Tumors of BRCAness were more likely to be hormone receptors negative (95.8% vs. 50.7%, P < 0.001), nuclear grade III (76.1% vs. 48.4%, P = 0.001) and triple-negative breast cancer subtype (91.6% vs. 42.5%, P < 0.001). Five-year disease free survival (DFS) (54.0% vs. 88.0%, P < 0.001) and overall survival (OS) (76.3% vs. 93.1%, P = 0.002) were significantly lower in BRCAness patients. In neoadjuvant chemotherapy subgroup analysis, clinical response rate for taxane-based regimen was significantly lower in BRCAness patients (58.3% vs. 77.8%, P = 0.041). Cox regression multivariate analysis showed that BRCAness was the independent prognostic factor for DFS (HR 2.962, 95%CI 1.184-7.412, P = 0.020), but not for OS (HR 2.681, 95%CI 0.618-11.630, P = 0.188). BRCAness is associated with specific characteristics and may suggest resistance to taxane-based chemotherapy. BRCAness can be used as a negative prognostic indicator for breast cancer.